The project ICE GENESIS looks towards the development of a new generation of 3D numerical tools for the simulation of in-flight ice accretion. This will allow to increase the prediction capabilities and accuracy of numerical simulations of ice accretion over aircrafts, allowing for a more precise evaluation of the effect that icing has over the aerodynamics of a body.
The project involves a collaboration between institutions performing experimental research on different phenomena, allowing to have a better understanding of the physics involved during the ice accretion process. This will result in the development of more accurate physical models and their subsequent implementation in modern numerical tools.
The role of the TU Braunschweig on the ICE GENESIS project is to investigate the influence of icing conditions over the formation of ice accretion roughness. For this, several ice shapes are generated in the Braunschweig Icing Wind Tunnel for different temperatures, particle sizes and exposure times. Then, the ice shapes are digitalized using the photogrammetry approach for their later analysis using numerical tools and statistical analysis.
The ISM conducts experimental research of in-flight ice accretion in the Braunschweig Icing Wind Tunnel. There, aircraft components are subjected to icing conditions, which allows the generation of an ice shape with certain geometrical characteristics depending on different parameters such as the velocity of the air flow, the static temperature, the water content, the size of water droplets or ice crystals and the exposure time.
In order to analyse the geometry of the resulting ice shape and the effects of the global and local icing conditions over it, its digitalization is required. From there, local statistical parameters such as the average value of the ice height or its r.m.s. can be computed, being the last used to measure the ice roughness.
Digitalization of an ice shape is often regarded very challenging due to the complexity of the ice geometry, as well as the optical properties of ice. An approach used by the ISM for this task is the photogrammetry method. This method consists on taking several photos of an ice shape from different angles and positions. Then, these photos are loaded into a program that proceeds to reconstruct a virtual geometry based on the common details that multiple photos present. The final product is the digitalized ice shape, which can be subsequently used for research and statistical analysis.